Sign up now
to enroll in courses, follow best educators, interact with the community and track your progress.
Questions (1-3)
1,258 plays

In this lesson, questions (1-3) have been explained.

Harshit Aggarwal
Cleared UPSC ESE twice with Rank 63 and 90 in mechanical engg. Got 99 percentile in GATE. Cracked ONGC, BHEL,ISRO, SAIL, GAIL successfully

Unacademy user
sir in reasoning except those topics,which topics should I study & practice from RS AGGARWAL book? because in RS AGGARWAL many topics.
Abhishek Pandey
a year ago
same topics which I have mentioned in syllabus
Karan Arela
a year ago
thank you.but in arihant(AFCAT) there is some others topics so I got a little bit confusion, which topics should practice.
how the mixture of ice and water when stirred by paddle entropy is zero
  1. COURSE: Detailed Explanation on Entropy Questions Lesson : Questions -(1-3)

  2. About me Graduated from NIT Nagpur in 2008 * Cleared Engineering Services Examination (ESE-UPSC) Exam Got the offer letter from most of the Maharatna and Navratna Companies , Cleared GATE Exam * Rate, Review, Recommend, Share Follow me on Unacademy at: aggarwal

  3. Question 1 On the basis of the first law fill in the blank spaces in the following table of imaginary heat engine cycles. On the basis of the second law classify each cycle as reversible, irreversible, or impossible Cycle Temperature Rate of Heat FlowRate of Efficiency work Source SinkSupplyRejectionOutput (a) 327 C 27 C 420 kJls 230 kJls .kVW (b) 1000 C 100oC ..kJ/min 4.2 MJ/min kW 65% 65% (c) 750 K 300 K ...kJ/s kJ/s | 26 kW | (d) 700 K300 K2500...kcal/h1 kW kcal/h

  4. Solution 1 Cycle Temperature Rate of Heat Flow Rate of Effici- Remark work enc Supply Sink 27 C Rejection 230 kJ/s max 50% rrev.possible Source (a) 327 C 420 kJ/s 190kW0.4523 (b)1000 C 100 C 12000 kJ/km max=70.7% irrev.possible 4.2 kJ/m 7800 kW | 65% ma,-60% rev. possible 750 K 300 K 43.33 kJ/s | 17.33 kJ/s | 26 kW | 60% 2500 kcal/h 1640 kcal/h (d)700 K 300 K 1 kW 4.4% irrev.possible

  5. Question 2 The latent heat of fusion of water at 0 C is 335 kJ/kg. How much does the entropy of 1 kg of ice change as it melts into water in each of the following ways: (a) Heat is supplied reversibly to a mixture of ice and water at 0 C. (b) A mixture of ice and water at 0 C is stirred by a paddle wheel

  6. Solution 2 (a) (AS) system - + 1x335 kJl HK Ice Water 273 K - 1.227 kJ/K (b) (AS) system 273 0 273

  7. Question 3 Two kg of water at 80 C are mixed adiabatically with 3 kg of water at 30 C in a constant pressure process of 1 atmosphere. Find the increase in the entropy of the total mass of water due to the mixing process (cp of water4.187 kJ/kg K)

  8. Solution 3 If final temperature of mixing is Tr then 2x (353-T) 2 kg 3 kg -3>< ( -303) 80 C 353 K30 C 303 K or T323 K (AS) system (AS)I (AS) Iu 323 323 303 32 +3 x4.187 x In 303 353 323 - 2 x 4.187 In 0.05915 kJ/K